Valve for pneumatic-dispatch-tube systems



(No Model.) 3 Sheets-She-Stl. A. B. CAMPBELL.

VALVE-FOR PNEUMATIC DESPATOH TUBE SYSTEMS. No. 551,616. Patented Dec. 17, 1895.

y \llil mmum (No Model.) 3 Sheets-Sheet 2. S A. B. CAMPBELL. v VALVE FOR PNEUMATIC DESPATGH TUBE SYSTEMS. .Nj 551,616.

Patented 1100.17, 1895.

(No Model.) 3 Sheets-Sheet 3. A. B. CAMPBELL. VALVE PO-R PNEUMATIC DESP-ATGH TUBE SYSTEMS.

No. 551,616. Patented D55. 17, 1895.

ANDREW EGRMEQM. PNOTO'l-"HQWASNINGIUN. DC.

UNITED STATES P TENT Qrrrcn.

AMMI B. CAMPBELL, OF LOIVELL, MASSACHUSETTS, ASSIGNOR TO THE METEOR DESPATCI'I COMPANY, OF PORTLAND, MAINE.

VALVE FOR PNEUMATIC-DISPATCH-T UBE SYSTEMS.

SPECIFICATION forming part of Letters Patent No. 551,616, dated December 17', 1895. Application filed December 10, 1894:. Serial No. 531,344. (No model.)

To all whom it may concern:

Be it known that I, AMMI B. CAMPBELL, of Lowell, county of Middlesex, and State of Massachusetts, have invented new and useful Improvements in Valves for Pneumatic-Dispatch-Tube Systems; and I hereby declare that the following is a'full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to certain new and useful improvements in valves for terminals for pneumatic-dispatch-tube systems, and isespecially adapted for those systems in which the carriers are propelled by suction-1;. e. by withdrawing the air-pressure from the front of the carrier as it travels through the system and it consists of certain novel features, arrangements and combinations hereinafter described, and particularly pointed out in the claims.

In the drawings, Figure 1 represents a perspective view of the terminal at the salesmans station. Fig. 2 is a side view of the interior of the terminal with one of the sides A re-;

moved. Fig. 3 is a vertical cross-section through the terminal on the line 50, Fig. 2. Fig. 4 is an inverted plan view of about onehalf of the bottom wall, showing the valve in its closed position. Fig. 5 is aside View of the same parts shown in Fig. 4, and showing in full lines the normal position of said valve and in dotted lines the position of the parts as the valve is opened by the impact of the carriers.

In the drawings like letters of reference refer to like parts throughout the several views.

The terminal A, which is known in the art as an upwardly-discharge terminal, can be used at either the cashiers or the salesmens stations, and consists of an outer curved guiding-wall A and flat sides A with a fiat bottom A, so that it presents to the view a box of an oval form, curved on top and with a flat bottom. There is provided on the inside of this box an inner .curved guiding-wall A which may be cast or otherwise secured to the sides A of the box, or it may be cast or otherwise secured to the bottom wall of the terminal.

and the bottom of said leaf 0'. in providing such a loose joint is that the tom wall of the terminal, and witlftlie outer curved guiding-wall A it forms between them for the carriers a passage A which is a continuation of the inlet-tube B, through which the carriers are sent to the terminal, and said tube is secured to the bottom wall A of the terminal between the outer wall A and inner wall A so that the carrier on entering the terminal passes up between the side walls and around the passage A to the valve 0 at the bottom of the terminal, which is opened by the impact of the carrier as it passes from the inlet-tube B around the passage A to said valve, and the air-current passes under the lower end of the wall A into the return-tube D,

through which the carriers are returned, and thus keeps up a continuous air-current in the system.

The main valve 0 consists of two leaves 0 and 0 covering respectively the openings 0 and O in the bottom wall A of the terminal. The said leaves are connected together by a lever 0 which at one end is secured to the leaf 0 by a screw 0 which leaves a small amount of play between the lever C The object leaf 0 may find a perfect seat against the leather packing C around the bottomof the opening 0 without regard to the exact position of the lever itself, it being borne in mind, of course, that thesuction against the leaf would have a tendency to draw it up firmly on all points, provided it is not prevented from so doing on account of its rigidity to the lever 0 as would be the case if the leaf .0 were attached solidly to the lever and the lever should become bent or. misplaced. The other end of the lever C is broadened, as shown at C and is secured to the leaf 0 by screws G which pass up through the end C thin metal plate C leather packing 0 and leaf 0 into the plate 0 ontop of the leaf C so that the lever 0 leaf 0? and plate C are rigidly and firmly held together.

The said plate 0 is providedon its upward end with two arms 0 which encircle the shaft 6, and are firmly secure'dthereto. Said shaft is mounted in the journals G secured to the upper side of the bottom wall A, and in said journals the shaft is adapted to revolve. A spring (1 is wound around the shaft 0 and has one of its ends bearing against the bottom wall A and the other end bearing on the top of the plate C", so as to assist in holding said leaf 0 in its closed position over the opening C. The leather packing 0 is held in close contact with the under side of the leaf (1 by the thin metal plate 0 A leather packing C is located around the upper edge of the opening C", and with said packing the leather packing (1 contacts and forms a close joint to prevent escape of air.

The two leaves 0 and C forming the valve (3, are connected together by the lever C in the manner shown, so as to provide a long leverage for the leaf (1 to permit its easy opening by the impact of the carriers-that is, the said leaf G provided with a longer leverage and swings farther out of the way of the carriers by providing a lever of the construction shown, and the force applied to the upper side of the leaf 0 by the diseharg ing-carriers is directly applied to the under side of the leaf 0 by means of the lever C. If the two leaves were connected together and pivoted in the center between the two openings C and C", the throw of the leaf (1 would be so short that it would be hard for the carrier to deliver from the terminal, whereas by increasing the leverage of the said leaf 0 the carrier more easily opens said leaf in order to deliver from the terminal, and the impact of the carrier on the leaf C is directly applied to the under side of the leaf C so as l to give a greater force in raising up the said *2 .w t leaf Q by means of the mcreased lucrage and the direct connection of the lever C to the bottom of the said leaf C a quicker action is given to the said leaf (1 when the front leaf 0' is opened by the impact of the carrier. The arrangement shown in the present case also provides a much more perfect arrangement of the valve and also insures the better fitting of the valve to prevent escape of air.

The leaf 0 fits closely against the bottom of the opening C and is exposed on its upper surface to the suction of the system, and its lower surface has a greater area exposed to the atmosphericpressure than the lower surface of the leaf C also exposed to said pressure. The carriers coming through the passage A- impact with the leaf 0 and open the same by the momentum thereof, and the valve moves toward a vertical position, as indicated by dotted lines, Fig. 5, as the carrier is discharged from the terminal. The leaf C when in its vertical position contacts with the under side of the inner wall A which closes the atmosphere, and the air-current continues through the tube 13, terminal A and return suction-tube l).

E represents an upright piece of thin metal having one end secured to the bottom wall A" and the other end resting against the inner side of the wall A, and it acts as a guide to prevent the carrier being drawn by suction into the opening beneath the inner curved wall as said carrier passes toward the valve 0 covering the outlet-discharge (1 of the terminal for the carriers. A preferable construction of said terminal consists in. casting the same in two upright parts, which are firmly held together by suitable bolts passing through the ears E on. the two parts of the terminal. Supposing this terminal is located at the cashiers station and it is desired to return a carrier to the salesman from whom it was sent, it is placed in a branch tube l connected with the return-tube I) and said branch tube F is covered by a self-closing clapper 1" hinged at F and at this point provided with a projection F,whieh limits the upward throw of the clapper, and on its opposite side with a finger F" by which the clapper is raised by the hand to permit the insertion of the carrier, and after the carrier has been pushed in. the clapper is drawn to its seatand held closed by the suction of the system.

As the area of the bottom of the leaf (J exposed to atmospheric pressure is less than the area of the bottom of the leaf 0 also exposed to said atmospheric pressure, the difference in amount of pressure on the bottom of the two leaves of the valve 0 will hold said valve 6 sullieiently tight against the openings (1 and C", thus preventing any leakage, and at the same time make it easy for the carrier to operate the leaf 0 of the valve C. If none of the bottom surface of the leaf were exposed to atmos flierie pressure, it would be difficult for the carriers to open the valve by their impact with the top of the leaf C; but the provision by which the amount of area on the bottom of the leaf C exposed to atmospheric pressure is less than the area on the bottom of the leaf 0 also exposed to atmospheric pressure not only holds the valve G closed, but at the same time permits the easy operation of the valve by the impact of the carrier on the top of the leaf 0. It is obvious that if the above arrangement were not provided to produce a difference of area of the bottom of the leaves 0 and C) exposed to atmospheric pressure and the area exposed to said atmospheric pressure on both leaves\ *as the same there would be produced an exact balance, which would not hold the valve to its seat, and the leaves would more or less swing away from the openin which. they were intended to close. Of course it will be understood that the construction shown simply illustrates one manner of carrying out my invention, as it is obvious that other constructions could be adopted which would embody the main principles of my invention.

I do not limit myself to the exact arrangement and construction shown, as the same maybe varied without departing from the spirit of my invention.

Having thus ascertained the nature and set forth the construction of my invention, what I claim as new, and-desire to secure by Letters Patent of the United States, is

1. In a pneumatic dispatch tube system, the combination with a terminal having an opening for the discharge of carriers, of a valve consisting of two leaves one of which normally closes said opening and is adapted to be opened by the impact of the carriers therewith, and a connecting rod to which said leaves areconnected, the said leaf which is opened by the impact of the carriers being connected to the said rod by a loose joint.

2. In a pneum atic dispatch tube system, the combination with a terminal having an opening for the discharge of carriers, of a valve consisting of two leavesone of which normally closes said opening and is adapted to be opened by the impact of the carriers, and a connecting rod'from said leaf to the other leaf which is pivoted in said terminal.

3. In a pneumatic dispatch tube system, the combination with a terminal having an open ing for the discharge of carriers, of a valve consisting of two leaves one of which normally close-s said opening and is adapted to be opened by the impact of the carriers therewith, and a connecting rod from said leaf to the other leaf which is pivoted in said terminal, the said connecting rod being connected to the leaf with which the carriers impact by a loose joint.

- 4:. A terminal for pneumatic dispatch tube systems having a base plate provided with a discharge outlet for the carriers, and with openings in which are secured the inlet and return tubes, curved inner and outer guiding plates forming a passage for the carriers through the terminal from the inlet tube to the discharge outlet, the said curved inner plate being cut away to provide communication for the air current between the said passage and the said return tube, a guide secured to the base plate and extending to the said curved inner plate to prevent the carrier being drawn by the suction from the said passage to the said return tube, and a valve normally closing the said discharge outlet in the base plate.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this 5th day of December, 1894.

AMMI B. CAMPBELL. Witnesses:

B. F. K. JENNINGS, SAML. E. KIMBALL. 

